The Neutron Flux Variation in the Earth’s Atmosphere Depending on the Solar Proton Flux

The Earth is continually exposed to the cosmic radiation of both solar and galactic origin. Solar eruption and solar activity may affect cosmic radiation flux density which has a secondary effect on the flux of particles in the atmosphere as well. Such one event was recorded in the last week of October 2003, where the measured dose rate of the cosmic radiation in the aircraft ATR 42 was 1.8 times higher than the average value of the other measurements. Later we found the data on an unusual solar activity in the mentioned time interval. Analysis of the increasing solar proton flux during the solar flare, as well as the decreasing neutron flux in the atmosphere (representing the galactic radiation), on May 14 and 15, 2005, showed a nonlinear correlation with the exponential equation of regression; this one described galactic ray modulation by solar flux during the short term variation of cosmic radiation.